1. Field of the Invention
The present invention relates to a system to guide a user to a destination object such as a surrounding plot of ground or a building via sound changes as the user moves. The invention particularly relates to a position guiding system, a position guiding method, and a sonic navigation system, which are suitable for sensorially understanding the positional relation between a destination object and the current position of the user via sound changes in an environment crowded with other objects or obstacles such as buildings.
2. Description of the Related Art
Conventionally, as systems to guide a user to a plot of ground or building in the vicinity of a target destination when a vehicle is traveling as well as to guide a user to the destination which a passenger heads for as the vehicle moves, a so-called car navigation system is widely known, and there was, for example, a navigation system loaded on a vehicle as released in the Japanese Patent Laid-open No. H10-197264.
This navigation system loaded on a vehicle possesses a CD-ROM which stores map data, a microprocessor which reads map data of a block surrounding the current position from the CD-ROM by calculating the current position of the vehicle using various sensors, a display processor which displays a map of a block surrounding the current position together with the current position on a display, and a sound generating device. The microprocessor has a function to set up any point on the map as a registered point on the instruction of a user and a function to detect a registered point within a given range from the current position. The sound generating device outputs an alarm sound from a speaker when a registered point is detected by the microprocessor.
Thus, even while driving a vehicle, a user can determine a registered point near the current position by a sound.
The present inventors have recognized problems residing in the conventional navigation systems. That is, in the case of the above-mentioned conventional navigation system loaded on a vehicle since its configuration is only to notify a user by a sound such as an alarm sound when a registered point which is a destination object enters within a given range from the current position of the vehicle, the user could know that the destination object was within a given range, but that was all that could be understood. It was difficult for the user to sensorially understand the relation between the destination object and the current position, such as how long it would take from the current position to the destination object.
For this reason, to ultimately lead the user to a destination, it was necessary to signify a route to the destination object by a sound or to show the destination object on a map on the display. In the former case, the user had to understand a route read aloud without any visual aid, and in the latter case, the user had to look at the display carefully.
Accordingly, a configuration in which a sound such as an alarm sound, etc. is outputted at a sound volume corresponding to a distance of a destination object from the current position can be considered. According to such a configuration, when a destination object enters within a given range from the current position of the vehicle, the nearer to the destination object the vehicle is, the higher the sound volume becomes. Conversely, the more distant from the destination object the vehicle is, the lower the sound volume becomes. Hence, the user can understand the positional relation between a destination object and the current position sensorially to some extent.
If a sound such as an alarm sound, etc. is outputted simply at a sound volume corresponding to the distance between a destination object and the current position, a realistic sense of distance to the destination object could be felt if the destination object is located in an open suburb. However, if the destination object, is located in a city crowded with many buildings, for example, at the rear of a building, a sense of distance to the destination object could be felt differently. In other words, to feel realistically a distance to a destination object in an environment crowded with many buildings, it is important to be able to understand not only the distance to the destination object but also geographical conditions of blocks surrounding the destination object.
The present invention is accomplished by taking notice of unsolved problems which these conventional techniques have. Among others, an object of the present invention is to provide a position guiding system, a position guiding simulation and navigation system and a position guiding method which are suitable for sensorially understanding the positional relation between a destination object and the current position in an environment crowded with many buildings by giving consideration to the distance to the destination object and the geographical conditions of a block around it.
To achieve the above-mentioned object, a position guiding method according to an embodiment of the present invention is a position guiding method which guides a user in reference to the positional arrangement of a target object, via sound changes as the user""s observation point moves, by (i) virtually disposing a sound source at the target object in a geographical data field, and (ii) outputting a simulation of sounds from the target object calculated in the geographical data field as if the target object actually emitted sounds. The method may (a) simulate actual propagation paths through which sound waves from the target object are propagated to the observation point while being influenced by objects or obstacles, and (b) considering the propagation paths, synthesize and output a simulation of sounds from the target object which the user would hear at the current observation point if the target object actually emitted sounds.
In this method, as the observation point moves, a simulation of sounds from the target object which would be heard at the observation point is generated and outputted, giving consideration to propagation paths through which sound waves from a sound source are propagated while being influenced by objects or obstacles.
Consequently, because propagation paths, through which sound waves from the target object are propagated while being influenced by objects or obstacles, are considered when sounds are synthesized, the positional relation between the positional arrangement of the target object and the observation point can be understood sensorially, including the geographical conditions of blocks surrounding the positional arrangement of the target object (the positional arrangement and size of the target object). In the above, the user hears actual sounds but, of course, the target object does not emit actual sounds. Simulation is conducted using a computer, and the actual geographical conditions are virtually reproduced in the computer, wherein the user and the target object are located in a geographical data field, and the target object emits sounds.
The geographical data filed may be in the form of a simulation map, preferably a three-dimensional simulation map. However, the geographical data field need not be visible to a user, as long as the user can input the coordinates of target objects in relation to the position of the user. The coordinates can be defined by the address, for example, which can be inputted by oral instructions or using a keyboard. If the geographical data field is displayed on a monitor, the user can select the target objects on the monitor. The geographical data field covers the positional arrangement of the user and the target object(s). The geographical data field can be configured using a GPS (Global Positioning System) using an orbiting satellite, a PHS (Personal Phone System) using many relay antennas, or any other means for identifying the positional arrangement of the user and the target objects. When the system receives positional signals of the user and the target objects, the system can configure the geographical data field using a database of a geographic information. The database can be preloaded in the system or can be obtained by accessing external sources via the Internet, etc.
Synthesized sounds can be outputted using speakers which can be installed in a vehicle itself, a helmet (e.g., for a motorbike), or a headset or headphone. Preferably, the system is installed in a vehicle, but the system can be portable.
Further, to achieve the above-mentioned purpose, a position guiding method according to another embodiment of the present invention is a method which guides a user in reference to the positional arrangement of a target object, via sound changes as the user""s observation point moves, by virtually disposing a sound source at a target object and by generating and outputting a simulation of sounds from the target object as if the sounds were emitted from the target object, which method comprises the step of (i) configuring a geographical data field in a computer system, (ii) designating a target object in the geographical data field as a sound source, (iii) designating an observation point in the geographical data field, (iv) defining the propagation of a sound from the sound source to the observation point as a sound signal which is a function of at least a distance from the sound source to the current observation point, (v) separating a sound signal arriving at the observation point into multiple audio element signals according to the direction of the sound source observed from the observation point, and (vi) reproducing and outputting to the user the multiple audio element signals whereby the user sensorially recognizes the position of the target object from the current observation point.
The present invention can also be applied to a position guiding system for guiding a user with reference to a target object via sound changes, comprising: (a) a positional information detector which obtains positional information for locating the position of the user""s observation point in a geographical data field; (b) a geographical data field-user interface which virtually disposes a sound source at the target object in a geographical data field; (c) a propagation path calculation unit which identifies propagation paths, through which sound waves from the target object are propagated to the observation point, based on the positional information obtained by the positional information detector, (d) a sound synthesizer which synthesizes a simulation of sounds as if the target object actually emitted sounds and the sounds were propagated to the user""s current observation point via the propagation paths, and (e) multiple sound output devices which outputs the synthesized sounds, said multiple sound output devices being arranged in different positions with respect to the positions of the user""s ears to enable the user to sensorially recognize the positional arrangement of the target object.
For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
Further aspects, features and advantages of the present invention will become apparent from the detailed description of the preferred embodiments which follow.